This definitions covers Key Definitions within Water Regulation for GCSE Biology. Topic 7: Water Regulation It is section 5 of 11 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 5 of 11
Practice
15 questions
Recall
20 flashcards
Key Definitions
ADH (antidiuretic hormone): A hormone produced by the hypothalamus and released by the pituitary gland that increases water reabsorption in the kidneys.
Osmoregulation: The regulation of water and salt levels in the blood and body fluids to maintain a constant internal water potential.
Nephron: The functional unit of the kidney; a microscopic tubule that filters blood and reabsorbs useful substances.
Filtration: The first stage in nephron function; blood is filtered under high pressure in the glomerulus, removing water, glucose, urea, and salts into the Bowman's capsule.
Selective reabsorption: The process by which useful substances (glucose, some water, salts) are taken back from the nephron tubule into the blood.
Urea: A waste product formed in the liver from the breakdown of excess amino acids; excreted in urine by the kidneys.
Excretion: The removal of metabolic waste products (such as urea, CO2, and excess water) from the body.
Collecting duct: The final region of the nephron; its permeability to water is controlled by ADH, determining how concentrated the urine will be.